Power transmitting device



Oct. 4, 1938. E. .A. ROCKWELL ET AL 2,131,787

POWER TRANSMITTING DEVICE 4 Sheets-Sheet 1 Filed July 5, 1934 ME .m v N\ !NVENT R EPW421912. OCXWELId'. BY Jbi/N J: 5!!! 1 517) ATTORNEY E. A. ROCKWELL ET AL POWER TRANSMITTING DEVICE Oct; 4, 1938.

Filed July 3, 1954 a Mfg 1. 2

4 Sheets-Sheet 2 INVENTO EDWARD A.

fiacjrms'zza Tali/V I 557161? ATTORNEY Oct. 4, 1938.-

Filed July 3, 1934' 4 Sheets-Sheet 3 ATTORNEY Oct. 4, 1938. E. A.YROCKVWELL ET AL 2,

POWER TRANSMITT ING DEVICE Filed. July 5, 1954 4 Sheecs$heet 4 g 125 5 a y) 1/ y .4

J J 3/ 1 I INVENTOR BY J'oHN JISHJVIL) ATTORNEY Patented on. 4, 1938 UNITED STATES PATENT OFFICE POWER TRANSMITTING DEVICE Edward A. Rockwell and John J. Shively, New York, N. Y., assignors to Patent Engineering Corporation, a. corporation of Delaware Application July 3,1934, Serial No. 733,598

14 Claims. (01. lb-263) This invention pertains to change speed power transmitting mechanisms, and particularly to automotive transmissions.

In our pending application filed February 1, 1934, Serial No. 709,319, is shown and described a change speed device making use of rolling friction between balls and races to provide one stage of a transmission. the said stage being controliable by an operative condition of the vehicle.

The purpose of the present invention is to provide a transmission in which all speeds are obtained through ball trains without gearing.

A further purpose is to provide a transmission of the above type in which all forward speeds may be controllable by an operative condition of the vehicle.

In pursuance of the above purposes suitable apparatus is herein described in accordance with the attached drawings, in which Fig. 1 is a longitudinal section of a four-speed transmission adapted to manual control of the lower gear ratios.

Fig. 2 is a transverse section of the same in the plane 2-2 Fig. '1. 5

Fig. 31s a detail view of the manual shift illustrating low and reverse positions.

Fig. 4 is a view of the same illustrating neutral position.

Fig. 5 illustrates second and third-speed posiao tions. I

Fig. 6 is a longitudinal section of a four-speed transmission controllable by fluid pressure in all forward stages.

Figs. '1 and 8 are fragmental views of the shifter rods.

Fig. 9 is a fragmental view of the torque wedge.

Fig. 10 is a detail view of a shift clutch.

Fig. 11 is a plan view of theH-gate.

Fig. 12 is alongitudinal section of an alternative structure to that of Fig. 6, showing the driving parts.

The transmission shown in Figs. 1 and 2 is provided with a main casing III to .which is attached a forward extension or member ll.v A' rear plate I2 attached to-main casing. l0 supports extension 2| guided by an i-i-slot or gate .22 in a stationary plate 23 and adapted to engage shifter forks 24, 25, 26 and 21, (Fig. 2) in a manner hereinafter described. The forks 26 and 21 are formed integrally with or suitably attached to .sleeves 28 and 29 respectively, which are rotat mentally in Figs. 7 and 8 and also slidable in the casing iii.

The casing Ill contains three guide rods -'of' which guide rod 45, Fig. 1, is typical. Shifter rings 46 and 41, Fig. 1," are longitudinally slidable' thereon and are fastened by anysuitable means such as pins 48 and 49 to shifter rods 43 and 40 respectively as shown in Figs. 1 and 8.

A driven shaft 50, Figs. 1 and 2, is piloted at the front end in a bearing 51 in the clutch shaft l1. A driven collar 52, splined to driven shaft 56 and backed by-a rear thrust nut 53 screwed on the latter, is supported in the rear bearing i3 which thereby, also supports the driven shaft 50. The shaft 50 also carries the usual speedometer worm 5.4 and coupling member 55.

Screwed to the shaft 50 behind the. pilot bearing 5i is a forward thrust nut 56 pressing against a spring ring 51 which in turn presses against a forward thrust bearing race ring 58 which is slidably keyed on the shaft 50.

A set of thrust balls 59 is disposedv between the race ring 58 and a rearthrust race member 60 which is rotatably mounted on shaft 50 and has external teeth 6|.

The member 66 is formed on its rear or right hand face with a series of angular recesses 62 as shown in Fig. 9. A driving ring 63, supported on a bushing 64 rotatable on the shaft 50, is formed with forward angular recesses 65, Fig. 9. A set of wedging balls 66 is engagedly disposed in the recesses-62 and 64 and is retained therein radially by a sleeve 61, Fig. 1. v

The driving ring 63 has an exterior angular race 68 engaging a set of driving balls 69 which in turn engage an interior angular race 16 of a rotative intermediate or reaction member 1 i The intermediate member 1! also has an exterior angular race 12 engaging a second set of driving balls 13 which engage the interior angular race 14 of a rotative member 15. Ball sets 68 and 13 are provided respectively with spiders or cages 16 and 11, rotatably mounted on shaft 50 and locked together by dog teeth 16 and 18.

The members 63 and 15, together with ball sets 68 and 13,-intermedite member H and interlocked cages 16 and 11 make up the-power transmitting elements of a speed reducing device of the type fully explainedin our previous application Serial No. 709,319 and hereinafter referred to as the first planetary set.

An exterior angular race 00 of the member 15 acts as a driving race for a second planetary se't comprising in addition thereto the ball trains 8| and 82, an intermediate or reaction member 08, a driven member 84 and the interlocked spiders or cages 85 and 86.

Driven member 04 in turn acts as the driving member for a third planetary set also comprising ball trains 81 and 88, intermediate member 88, driven member 80 and interlocked spiders or cages SI and 82. I

The driven member 80 of the third planetary set has a rear race 83 engaging a set of reversin balls 84 which also engage the race 85 of final driven collar 52. Reversing balls 84 are provided with a separator cage 86 having exterior teeth 81.

A sleeve 88 has interior teeth 88 slidable on the teeth 81 of cage 36, and is formed with a circumferential groove I00 engaged by a finger IOI on shifter rod 44 as shown in Fig. 7. Sleeve 88 also has exterior teeth I02 on which is slidable 9. second interiorly toothed sleeve I03. Sleeve I03 is provided with a circumferential groove I04 engaged by finger I05 on the shifter rod 38. Sleeve I03 carries short exterior teeth I06 adapted to engage interior teeth I01 of a ring I08 fastened to the casing I 0. The intermediate or reaction member 83 of the second planetary set contains a series of circumferential sockets I08 as shown in Fig. 10, containing balls IIO retained therein by the shifter ring 46. The shifter ring 46 has an interior cylindrical portion or idling bore III extending through part of its length, and a series of internal teeth II2 adapted to mesh between the balls I I0 so as to lock the member 08 to the shifter ring 46.

Intermediate member 08 carries a similar set of balls II3 adapted to be engaged by teeth H4 in the shifter ring 41. Driven member 80 also carries a set of clutching balls II5 adapted to be engaged by teeth 88 of sleeve 80, the teeth 88 being cut away at II6 to provide an idling race for balls II5. A similar set of clutching balls II1 socketed in the driven collar '52, is adapted to be engaged by forward'interior teeth I I0 in the second sleeve I08. s

From the foregoing it will be seen that when ring 46 is moved to the left by rod 48 (Fig.8) the teeth II2 mesh with the balls III to lock member 08 to the ring 46 which is restrained from turning by stationary rods 45. Similarly, when ring 41 is moved to the left by rod 40. the teeth II4 mesh with balls III to lock intermediate member 88. 1

when the sleeve 86 is moved either to left or right by rod 44 (Fig. 7) the balls II5 are engaged driven collar 52 through the first sleeve 88. If sleeve I03 is moved to the left its exterior teeth I06 engage teeth I01 of the ring I08, thus locking the cage 86 to the casing I0.

The spaces between teeth adapted to engage the various sets of clutching balls may be outwardly inclined as illustrated at I I8, Fig. 1, thereby tending to hold the balls and,- teeth firmly meshed under load.

The shifter rods are provided with suitable locating devices such as notches I20 and ball latch I2I, Fig. 'I.

Slidably splined to the circumference of the first intermediate race member 1I, Fig. 1, is a brake plate I22 having frictional facings I23 and I24. A pressure plate I25, having fastened thereto guide pins I26 slidably retained in lugs I21 of the forward casing section II, is adapted to engage the facing I23 so as to force the facing I25 into frictional engagement with a stationary ring I28. Tension springs I28 attached to pins I26 serve to retract the plate I25.

A yoke I30 has shafts I3I and I32. Fig. 2, journalled respectively in casing section II and a bushing I33 therein. Shaft I32 extends out through the casing section II and carries an exterior operating lever I34. Downwardly extending levers I35 and I36 on yoke I30 engage extensions. I31 and I33 of the pressure plate I25.

Referring to Figs. 3, 4 and 5 in which the shifter forks are shown diagrammatically inplan view in the various shift positions referred to the H- gate plate 22, Fig. 11, the forward direction of car motion is indicated by the arrow, Fig. 11. The forks 24 and 25 are of simple type, having central notches I 8 and I40. The intermediate fork 21 has an a gular slot I4I substantially spanning the space between forks 24 and 25 and terminating in a notch I42 adapted to underlie-the notch I40. The lower fork 26 has an inclined slot I43 normally underlying the slot I4I inintermediate fork 21.

Referring again to Figs. 1 and 2, the shaft I1 has formed at its rear end a cup I44 having internal teeth I45 meshing with the teeth 6I on the thrust race member 60.

Referring to Fig. 6 in which parts identical with those already described are indicated by the same numbers, the intermediate, race member H of the first planetary set carries the brake plate I22 as previously noted.

The intermediate or reaction members I46 and I41 of the second and third planetary sets also have slidably splined thereto the brake plates I48 and I4! respectively.

Three or more guide rods I50, only one of which is shown as the others are identical therewith, are supported in 'circumferentially spaced relation in the main casing I5I and forward casing section I52. Slidifble on the rods I50 are a forward pressure plate I53, a double-faced pressure plate I54 disposed between brake plates I22 and I40, and a second double-faced pressure plate I55 disposed between brake plates I40 and I48. A back friction plate I56 is fixed to the casing I5I.-

Coil springs I51 space the pressure plate I58 and plate-I54 apart. Springs I56, heavier than I51, space plates I54 and I55. apart, while still heavier springs I58 space the plate I55 to the left from the stationary friction plate I56. The springs just described thus normally keep the brake plates free of the friction applying plates.

The driven member I66 of the third planetary set, which is also the driving race member for the reverse balls 84, has external spline teeth I600. 1|

member 15 at a rotative The cage |8I for the reverse balls 94 has slidably splined thereto a ring I62 having a groove I63 engaged by a finger I 64 on able in the casing |5I and provided with an external control connection of any suitable type such as a manuallyoperable lever I66.

External to the forward casing member I 52, but secured thereto is a cylinder I61 in which ls slid able a sealing piston I68. A link rod I69, pivoted at I to the piston I68, extends through the head I1I. of cylinder I61 and is pivotally connected to the end of the exterior yoke lever I34 at I12. A heavy tension spring I13 stressed between the pivot I12 and a lug I14 formed on the casing I5I, urges the lever I34 and piston I68 to the right.

The cylinder I61 is closed at the left by a sealing end plate I15 into which is connected a threeway valve I16 having, an operating lever I11 and a rotatable port plug 111a. The cylinder head I1.I containsa vent hole I 18. The rod I69 may be provided with the usual dust boot I 19.

The three-way valve" I16 controls a port I 80- leading into the cylinder I61,an atmospheric vent port I8I, and a port I82 leading to a tube I83 adapted to be connected to a source of vacuum, preferably the inlet manifold of an automotive engine (not shown).

The operation of the device is as follows. referring first to the type shown in Fig. 1.

When power is applied through the shaft I1 I and cup I44 the member 60 is revolved and carries with it the driving ring 63 due to the balls 66 confined in the angular recesses, 62 and 65. The

spring 51 being initially flexed between the thrust race ring 58 and the nut 56, places an axial thrust through the driving parts which exerts a tractive friction between all the balls and races back to the driven member 52. As the load builds up the balls 66 tend to 'roll up the faces of the recesses 62 and 65. A wedging action is thus set up which exerts an increased axial thrust proportional to the torque transmitted by the balls '66. The angles of the recesses 62 and 65 are made such that the thrust set up, which is resisted by the thrust balls 59, is sufficient to prevent slip between the driving parts at all loads.

The drive through the first planetary set which may be either direct or with a reducing ratio, takes place as follows:

For a reduced ratio, the yoke I30 is swung counter-clockwise by exterior means such as spring I13, Fig. 6, acting through the lever.-| 34. The extensions I35 of yoke I30 move the pressure plate I 25'to the right, engaging the friction facing The driving race 68 now rolls the balls 69 forward on the race 10, carrying with them the spider 16. The spider 11, being interlocked with 16 by the dog teeth 18 and 19, is carried around with it. The second balls 13 are thus also carried around, rolling on the race 12 and driving the speed reduced from that of the driving member 63 in the proportion of the effective diameters of races 68 and 14.

When the brake plate I22 is released, leaving the intermediate member free to rotate, no stationary torque reaction is applied between the driving member .63 and member 15. No drive at reduced speed is therefore possible between these members, consequently the device'must either idle or drive atdirect'or one to one ratio. For idling to take place, the cages 16 and 11 must revolve at different speeds relative to the intermediate mema shifter rod I65 slidber 1|. This however, is impossible, as the cages are locked together by their dog teeth. As a consequence the balls, races and cages lock together and revolve as a unit, transmitting a direct drive.

In the same manner, the second planetary set may be made to transmit a reduced or a direct drive from themember 15 to member 84 by restraining or releasing the member 83 by means of the shifter ring 46. Similarly meshing or unmeshing the shifter ring 41 causes the third planetary set to transmit a reduced or a direct drive to the member 90.

When cage 96 is locked to member 90 by means of the sleeve 98 as previously described, the reversing balls 94 cannot roll, and since the thrust of the torque wedge balls 66 prevents slip, the driven ring 52 and shaft 50 are driven forward at the speed of member 90.

A similar direct drive occurs if the cage 96 is locked to the driven member 52 by the second position as shown in Fig. 1, and the cage 96 is held stationary by sliding the second sleeve I03 into engagement with the ring I08, the balls 94 transmit a reverse drive to the driven member 52 and shaft 50. The operation of the shifting mechanism to give the various desired speed ratios is as follows:

Assuming the first planetary set to be held in reducing ratio by the gripping of brake plate I 22 as previously explained, the lower extension 2| of manual lever I9 is movedto the position in the H-gate shown in full lines in Fig. 11. It will be noted that whenever extension 2| is in the cross slot 22 of the H-gate, both forks 24 and 25 are in middle position, in which both sleeves 98 and 03 are in neutral position as shown in Fig. 1. An extension 2| is guided straight to the-left, Fig. 11, by slot 22, it engages the angular slots in forks 26 and 21, swinging both forks 26 and 21 toward the rear as shown in Fig. 3. This movement is communicated by the sleeves 28 and 29, levers 3| and 32, and rods locking the intermediate members 83 and 89 of the second and third planetary sets. Extension 2| having engaged the fork 24, is moved backward, causing the second sleeve I03 to lock the now in low or first speed, the drive taking place through the combined reduction of the three planetary sets.

If fork 24 is moved to its forward position as indicated by the lower dotted position in Fig. 3, the sleeve I03 locks the cage 96 to the stationary ring. I08, giving a reverse drive as previously explained.

When the extension 2| is moved to the right through the slot 22 it throws the forks 26 and 21 forward, thus releasing the intermediate members 83, 89 and engages the fork 25 in the latters neutral position as shown in Fig. 4. A forward movement of extension 2| moves both forks 21 and 25 forwardre-locking the intermediate member 89'and causing the sleeve 98 to lock the cage 96 to the member 90. The drive now takes place through the first and third planetary reductions while the second planetaiysetrevolves as a unit, giving a second speed.

when the extension 2| is moved back to the rear position indicated in Fig. 5 by dashed lines, the third planetary set is released and the cage 96vagain locked to the member 90. The drive now takes place through the single reduction v 43 and 40 to the shifter rings 46 and 41 which are moved forward,

'cage 96 to the driven member 52. The device is a of the first planetary set, the second and third sets revolving as units, giving a third speed.

To allow a fourth speed or direct. drive, the brake plate I22 is released by operation of the exterior lever I34, which may be effected by a fluid pressure actuated piston such as I68, Fig. 6. When vacuum is applied to the left of piston I68 the increase of effective atmospheric pressure on the right thereof moves the piston I68 to the left, overcoming the tension of spring I13 to swing the lever I34 and release the brake as previously explained. All planetary sets now revolve as a unit, and a direct drive occurs through the transmission.

In the type of transmission shown in Fig. 6, all planetary sets are controlled by brakes, the only manual shift being that required to slide the sleeve I62 into mesh with the member I69 or with a stationary ring I84 .to give forward and reverse drives respectively.

Assuming the cylinder I61 to be connected to the inlet manifold of the motor, the vent valve being shut as shown in Fig. 6, the effective pressure on the right side of piston I68 will be dependent on the inlet vacuum which is dependent on the speed and torque of the motor. When the vacuum rises during light loading and at high motor speeds under moderate loads, the pressure on the right side of piston I68 holds the latter to the left against the pull of the spring I13. The springs I51, I58 and I59 hold the various pressure plates apart, freeing the brake plates I22, I48 and I49 so that the device revolves as a unit in direct or highest driving ratio.

As the motor load increases the vacuum falls, decreasing the resistance of the piston I68 to the spring I13 until when a certain loading is reached as predetermined by the proportion of the parts and strength of the springs, the spring I13 overcomes the relatively light springs I51 and causes the brake plate I22 to be gripped between the pressure plates I53 and I54. The intermediate member 1| is thereby stopped causing the first planetary set to drive at reduced ratio and placing the transmission in third speed.

Similarly a further increase in load further increases the effectiveness of spring I13 which applies'increased pressure through the first pressure plate I53, first brake plate I22 (which is slidably splined to H as previously noted), and second pressure plate I54 to the springs I58 until the latter are overcome. The second brake plate I48 is thereby gripped, causing the second planetary set also to drive at reduced speed and placing the transmission in second speed ratio.

Similarly, a furtherincrease in load causes the springs I59 to be overcome to bring the third planetary set also into reducing operation, the drive now occurring through the three combined reductions which thereby constitute low or first speed.

Under decreasing. load the above actions are reversed, the springs I59, I58 and I51 expanding.

in succession to free their corresponding brake plates and cause the drive to occur through successively smaller reductions up. to the direct drive.

The device shown in'Fig. 6 thus constitutes an automatic transmission, the various speed ratios being brought into action in response to the fluid pressure effective on the back of piston I68, which pressure is a function of the speed and torque of the engine. If it is desired to modulate the action of the automatic controlling device the valve lever I11 may be swing to the right until the vent port I8I is cracked to any degree de-' IN to the cylinderreleased.

sired, thus lowering the vacuum on the left of piston I68 for any given running condition and causing the downward ratio changes to occur at correspondingly lighter motor loads. If it is desired to prevent release of the brake plates irrespective of operating speeds and loads, as for instance while running in reverse, the vent port I8I is opened wide. Both sides of piston I68 are then under atmospheric pressure, and at the same time the port plug I11a closes the port I82 leading to the inlet manifold, thus avoiding unnecessary dumping of air into the fuel mixture.

To hold the transmission in any desired ratio irrespective of engine operation, the valve handle I11 may be swung to the left, closing the port I61, which is thereby deadended to the left of piston I68. No effective pressure change can occur on the piston under this condition, and the device retains the speed ratio in which it was operating when the valve I16 was closed.

The changes from one ratio to another being accomplished by frictional means, occur without shock, each planetary set passing through an infinite number of ratios between direct drive and its maximum reduction as its brake is applied or The range between complete gripping of one plate and the gripping of .the next is predetermined by the relative strength of the springs I51, I58 and I59. If desired, these strengths may be made such that the stopping of successive plates overlaps, in which case the transmission operates with a continuously variable ratio from direct to low speed drive.

While the springs I51, stronger springs I58 and strongest spring I59 are shown applied respectively to the brakes operating the first, second and third planetary sets, this arrangement is only illustrative, since due to the application of the pressure through the entire set of braking members at the same time the springs will yield successively and throw their planetary sets into action in the manner described irrespective of their location. For example, if desired the springs I59 may be made weakest and I51 the strongest. In this'oase the third planetary comes into action first as the load increases, the second and first sets following successively. An advantage of this arrangement is that each brake is required to overcome a minimum of torque while bringing its intermediate or reaction member to a stop, as all drive up to the planetary set being controlled is occurring directly from the engine.

By the use of the fluid pressure piston I68 to control the first planetary set of the transmission shown in Fig. 1, as previously described, the operation of this type of transmission is also rendered automatic between direct and third speed, the vent valve I15 being employed to hold the first reduction when operating in the lower ratios and/or to modulate the automatic action. If desired, the valve shown in Fig. 6, in which case automatic shifting occurs between two ratios in all manual shift positions. I

-Plg.' 12 shows an alternative arrangement of the rotative parts of the transmission shown in Fig. 6, the torque wedge balls 66 being located between the rear race member I85 and the final driven member I86. The power is applied by the cup I44 directly to the driving race member I81 of the first planetary set. With-this arrangement the wedging action necessary to prevent slip is set up by the output torque and is therefore proportional to the latter. In the higher speed may be left in the. position tion, a series of planetary sets in operative conand direct driving, therefore, the rolling parts are not called upon to withstand the thrust necessary to prevent slip in lower ratios. It is obvious that this location of the torque wedge is equally applicable to the transmission shown in Fig.

While the invention is illustrated in preferred form it is not limited to the exact structures shown asvarlous modifications may be made without departing from the scope of the appended claims."

What is claimed is:

1. In a power transmitting device adapted to be driven by an automotive engine, in combination, a power input member, a power output member, a series of planetary sets operatively connected between said members and having each a reaction member, means controllable by an operative condition of said engine to restrain the rotation of said reaction member, said planetary sets being individually adapted to drive at reduced speed when said reaction members are restrained from rotation and to effect a direct drive when said reaction members are released, and means to modify the control of said restraining means by said operative condition.

2. In a power transmitting device, in'combinanection and having each a reaction member,

braking means adapted to engagesaid member to effect a speed change and individual means normally holding said braking meansout of engagement with said member, and means to apply an increasing force to all said braking means and thereby successively disable said holding means.

3. In a power transmitting device, in combina-- tion, a series of planetary sets in operative connection and having each a reaction member,

. braking means adapted to engage said member to effect a speed change and individual means normally holding said braking means out, of engagement with said member, and means to apply an increasing force to all said braking means and thereby successively disable said holding means, said planetary sets being adapted to revolve as units when said braking means are out of engagement. 1

4. In a power transmitting device, .in combination,three planetary sets connected in series having each a'reaction member, said planetary sets being adapted to normally revolve as units,

means controllable by fluid pressure to restrain the reaction member of said first set from rotation, and manually controllable means to selectively restrain the rotation of the eaction members of said second and third planetary sets whereby a plurality of speed reductions may be effected. 1

5. In a power transmitting device, in combination, three planetarysets connected in series having each a reaction member, said planetary sets being adapted to normally revolve as units, means controllable by fluid pressure to restrain the reaction member of said first set from rotation, manually controllable means to selectively restrain the rotation of the reactionflnember of said second and third planetary sets whereby a plurality of speed reductions may be effected, and means to reverse the rotative direction '0! drive through said device. 4

6. In a power transmitting device, in combination, a plurality of planetary sets in series, each set comprising a driving race member, a row of driving balls irictionally engaging said driving race member, a driven race member, a second row of driving balls frictionally engaging said driven race member, an intermediate reaction race member frictionally engaging said first and second rows of balls. cages circumferentially spacing said first row of balls, and a second cage circumferentially spacing said second row of balls and rotatively locked to said first cage, and

means operable to restrain said reaction memrace member frictionally engaging said first and second rows of balls, a cage circumferentially spacing said first row of balls, and a second cage circumferentially spacing said second row of balls and rotatively locked to said first cage, means to restrain said reaction members from rotation, said planetary sets being individually adapted to normally revolve as units and to drive at reduced speed when said reaction members are restrained from rotation, and means to reverse the rotative direction of drive through said'device.

8. In-a power transmitting device, in combination, a plurality of planetary sets in series, each set comprising a driving race member, a row of driving balls frictionally engaging said driving race member, a driven race-member, a second row of driving balls frictionally engaging said driven race member, an intermediate reaction race member frictionally engaging said first and second rows of balls, a cage circumferentially Spacing said first row of balls, and a second cage circumferentially spacing said second row of balls and rotatively locked to said first cage, and means operable to successively restrain said reaction members from rotation, said planetary sets being individually adapted to normally revolve as units and to drive at reduced speed when said reaction members are restrained from rota- ,row of driving balls frictionally engaging said driven race member, an intermediate reaction race member frictionally engaging said first and second rows of balls, a cage circumferentially spacing said first row of balls, and a second cage circumferentially spacing said second row of balls and rotatively locked to said first cage, and means controllable by fluid pressure to successively restrain said reaction members from rotation, said planetary sets being individually adapted to normally revolve as units and to drive at reduced speed when said reaction members are restrained from rotation. I

10. In a power transmitting device, in combination, a plurality of'change speed devices in series, individual means operable at different pressures to frictionally control said change speed devices, and means to apply a common variable pressure to said individual means.

11. In a. power transmitting device, in combination, a plurality of change speed devices in series, individual means operable at different pressures to frictionally control said change speed devices, and means controllable by fluid pressure to apply a common variable pressure to said individual means.

12. In a power transmitting device adapted to be driven by an automotive engine, in combination, a plurality of change speed devices in series, individual means operable at different pressures to control said change speed devices, and means controllable by an operative function of said engine to apply a common variable pressure to said individual means.

13. In a power transmitting device adapted to be driven by an automotive engine, in combination, a plurality of change speed devices in series,- individual means operable at difl'erent pressures to control said change speed devices, and means controllable by a function of said engine to apply a common variable pressure to said individual means, said change speed devices being adapted to normally efiect a direct drive.

14. In a power transmitting device in combination, a driving member, a driven member, a series of planetary sets adapted to transmit power from said driving to said driven member and having each a reaction member, and means to restrain the rotation of said reaction members,

said planetary sets being individually adapted to drive at reduced speed when said reaction members are restrained from rotation and to effect a direct drive when said reaction members are released, by reaction on the reaction members while the reaction members are moving in the same direction as the driven member.

EDWARD A. ROCKWELL. JOHN J. SHIVELY. 

